Limits...
Investigation of photocatalytic degradation of phenol by Fe(III)-doped TiO2 and TiO2 nanoparticles.

Hemmati Borji S, Nasseri S, Mahvi AH, Nabizadeh R, Javadi AH - J Environ Health Sci Eng (2014)

Bottom Line: In addition, the effects of various operational parameters on photocatalytic degradation, such as pH, initial concentration of phenol and amount of photocatalyst were examined and optimized.At all different initial concentration, highest degradation efficiency occurred at pH = 3 and 0.5 g/L Fe(III)-doped TiO2 dosage.With increase in initial concentration of phenol, photocatalytic degradation efficiency decreased.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Environmental Health Engineering, School of Public Health and Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.

ABSTRACT
In this study Fe (III)-doped TiO2 nanoparticles were synthesized by sol-gel method at two atomic ratio of Fe/Ti, 0.006 and 0.034 percent. Then the photoactivity of them was investigated on degradation of phenol under UV (<380 nm) irradiation and visible light (>380 nm). Results showed that at appropriate atomic ratio of Fe to Ti (% 0.034) photoactivity of Fe(III)-doped TiO2 nanoparticles increased. In addition, the effects of various operational parameters on photocatalytic degradation, such as pH, initial concentration of phenol and amount of photocatalyst were examined and optimized. At all different initial concentration, highest degradation efficiency occurred at pH = 3 and 0.5 g/L Fe(III)-doped TiO2 dosage. With increase in initial concentration of phenol, photocatalytic degradation efficiency decreased. Photoactivity of Fe (III)-doped TiO2 under UV irradiation and visible light at optimal condition (pH = 3 and catalyst dosage = and 0.5 g/L) was compared with P25 TiO2 nanoparticles. Results showed that photoactivity of Fe(III)-doped TiO2 under visible light was more than P25 TiO2 photoactivity, but it was less than P25 TiO2 photoactivity under UV irradiation. Also efficiency of UV irradiation alone and amount of phenol adsorption on Fe(III)-doped TiO2 at dark condition was investigated.

No MeSH data available.


Related in: MedlinePlus

Effect of initial concentration of phenol on the photocatalytic degradation of phenol. Fe(III)-doped TiO2 = 0.5 g/L, pH = 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4125378&req=5

Figure 5: Effect of initial concentration of phenol on the photocatalytic degradation of phenol. Fe(III)-doped TiO2 = 0.5 g/L, pH = 3.

Mentions: It is well known that the initial concentration of reactant plays an important role on photodegradation of organic compounds [16]. The influence of initial phenol concentration on photocatalytic degradation at five levels (5, 10, 50, 100 and 500 mg/L) was investigated (Figure 5). As shown in figure, photocatalytic degradation decreases with increasing initial concentration. Decrease in degradation rate at higher concentration is attributed the fact that light absorbed by the phenol is more than that of Fe(III)-doped TiO2. Thus light absorbed is not effective to carry out the degradation [6,17]. Further, the equilibrium adsorption of phenol on the catalyst surface active site increases and more and more molecules of phenol are adsorbed by the catalyst [6,17,18]. As a result, competitive adsorption of OH− on the same site decreases and consequently the amount of •OH and O2•− on the surface of catalyst decreases. For all initial phenol concentrations, the catalyst dosage, irradiation time and intensity of light were constant. Since the generation of •OH does not increase, the probability of phenol molecules to react with •OH decreases and hence, a decrease in the degradation efficiency is observed [17]. In fact, with progress in degradation reaction especially at high initial concentration, some intermediates are formed and competitively adsorbed on the catalyst surface and also competitively react with oxidant species [18-20]. Moreover, the oxidized intermediate can react with reducing species (e.g. electrons) yielding back phenol which finally results in a decrease of the degradation rate of the substrate [21].


Investigation of photocatalytic degradation of phenol by Fe(III)-doped TiO2 and TiO2 nanoparticles.

Hemmati Borji S, Nasseri S, Mahvi AH, Nabizadeh R, Javadi AH - J Environ Health Sci Eng (2014)

Effect of initial concentration of phenol on the photocatalytic degradation of phenol. Fe(III)-doped TiO2 = 0.5 g/L, pH = 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4125378&req=5

Figure 5: Effect of initial concentration of phenol on the photocatalytic degradation of phenol. Fe(III)-doped TiO2 = 0.5 g/L, pH = 3.
Mentions: It is well known that the initial concentration of reactant plays an important role on photodegradation of organic compounds [16]. The influence of initial phenol concentration on photocatalytic degradation at five levels (5, 10, 50, 100 and 500 mg/L) was investigated (Figure 5). As shown in figure, photocatalytic degradation decreases with increasing initial concentration. Decrease in degradation rate at higher concentration is attributed the fact that light absorbed by the phenol is more than that of Fe(III)-doped TiO2. Thus light absorbed is not effective to carry out the degradation [6,17]. Further, the equilibrium adsorption of phenol on the catalyst surface active site increases and more and more molecules of phenol are adsorbed by the catalyst [6,17,18]. As a result, competitive adsorption of OH− on the same site decreases and consequently the amount of •OH and O2•− on the surface of catalyst decreases. For all initial phenol concentrations, the catalyst dosage, irradiation time and intensity of light were constant. Since the generation of •OH does not increase, the probability of phenol molecules to react with •OH decreases and hence, a decrease in the degradation efficiency is observed [17]. In fact, with progress in degradation reaction especially at high initial concentration, some intermediates are formed and competitively adsorbed on the catalyst surface and also competitively react with oxidant species [18-20]. Moreover, the oxidized intermediate can react with reducing species (e.g. electrons) yielding back phenol which finally results in a decrease of the degradation rate of the substrate [21].

Bottom Line: In addition, the effects of various operational parameters on photocatalytic degradation, such as pH, initial concentration of phenol and amount of photocatalyst were examined and optimized.At all different initial concentration, highest degradation efficiency occurred at pH = 3 and 0.5 g/L Fe(III)-doped TiO2 dosage.With increase in initial concentration of phenol, photocatalytic degradation efficiency decreased.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Environmental Health Engineering, School of Public Health and Center for Water Quality Research (CWQR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.

ABSTRACT
In this study Fe (III)-doped TiO2 nanoparticles were synthesized by sol-gel method at two atomic ratio of Fe/Ti, 0.006 and 0.034 percent. Then the photoactivity of them was investigated on degradation of phenol under UV (<380 nm) irradiation and visible light (>380 nm). Results showed that at appropriate atomic ratio of Fe to Ti (% 0.034) photoactivity of Fe(III)-doped TiO2 nanoparticles increased. In addition, the effects of various operational parameters on photocatalytic degradation, such as pH, initial concentration of phenol and amount of photocatalyst were examined and optimized. At all different initial concentration, highest degradation efficiency occurred at pH = 3 and 0.5 g/L Fe(III)-doped TiO2 dosage. With increase in initial concentration of phenol, photocatalytic degradation efficiency decreased. Photoactivity of Fe (III)-doped TiO2 under UV irradiation and visible light at optimal condition (pH = 3 and catalyst dosage = and 0.5 g/L) was compared with P25 TiO2 nanoparticles. Results showed that photoactivity of Fe(III)-doped TiO2 under visible light was more than P25 TiO2 photoactivity, but it was less than P25 TiO2 photoactivity under UV irradiation. Also efficiency of UV irradiation alone and amount of phenol adsorption on Fe(III)-doped TiO2 at dark condition was investigated.

No MeSH data available.


Related in: MedlinePlus